Quarterback Carson Palmer stepped on a field for the first time in 313 days and he left again early with a mild left ankle sprain in his fourth and last possession of the Bengals' rocky preseason opener here Friday night here at the Superdome in which New Orleans took a 10-0 lead in the second quarter. Palmer, who completed seven of 11 passes for 133 yards, also suffered an interception on an ill-advised ball to linebacker Jonathan Vilma in traffic on third-and-five that ended the third drive. A relaxed Palmer had a smile on his face as he spoke with trainers, but there was no word on his availability for next week..................